Universal bar for typewriters



June 25, 1963 E. v. BYERS 3,095,077

A UNIVERSAL BAR FOR TYPEWRITERS Filed Feb. 5. 1960 42M, faz-@MyW ATTOP/VE' V5 United States 3,095,077 Patented June 25, 1B63 ice 3,095,077 UNIVERSAL BAR FOR TYPEWRITERS Edward Victor Byers, 1.6 Barrack Lane, The Park, Nottingham, England Filed Feb. 5, 1960, Sex'. No. 7,014 4 Claims. (Cl. 197-97) This invention relates to the universal -bar or bail of typewriting machines in which the type bars are pivoted `around a circular arc and varranged to strike at a common centre lagainst `a platen carrying the paper or other medium upon which the typed impression is to be taken.

Such machines are most usually provided with an arcuate spring loaded universal bar situated at the rear of the slotted segment plate in which the type bars are supported, and mounted in such a manner as to permit engagement with identical cam shaped protrusions formed on each type bar near the pivotal arc whenever the type bars are caused to strike the platen. The universal bar yis thus caused to oscillate at each typing stroke, its motion Vbeing utilized to operate the paper carriage spacing, and sometimes other mechanism of the machine. Another function of `the universal bar is Vto repulse the type bars from the platen.

To ensure consistent and high speed operation of the machine, it 'is particularly important that the carriage spacing mechanism or escapement should be operated by each and every typing stroke when the type blocks have arrived at the same predetermined point close to the platen. It is also important that each and every type bar should rst engage the universal -bar at the same angular distance from the platen during its travel thereto in order that the repulsing effect to the type lbars may be uniform over the whole set of bars, failure to provide this property being reflected in an unpleasing irregularity in the operation of the keys of the machine. In order to fulll these requirements it has, hitherto, been usual to mount the universal bar in such a way that its engaging face would remain sensibly parallel to its rest position throughout its oscillation, the realization of which condition usually necessitates the use of numerous small and accurately formed parts.

The invention has as its object the provision of a universal bar mechanism which exercises the same funtions as a parallel motion bail using only a relatively small number of parts.

According to this invention the universal bar or bail comprises a plate disposed at the back of the type bar segment, the plate having `an arcuate ange on one edge which is engaged by abutment-s on the type bars when the latter are operated to move the plate about fulcrum points disposed on an arc, the movement of the plate being adapted to operate the carriage escapement. The movement of the plate may be transmitted directly to the carriage escapement or it may operate a pivoted arm connected thereto.

The invention will now be more particularly described with reference to the accompanying drawings in which:

FIG. l yis a cross sectional elevation land FIG. 2 is a rear elevation of a type bar segment having a universal bar or bail according to this invention.

FIG. 3 is a cross sectional elevat-ion of a type bar segment showing the movement of the universal bar or bail by a type bar.

Like numerals indicate like parts throughout the drawings.

In carrying out this invention the type bars 1 are pivoted in a type bar segment 2 in the usual manner. The type bars are arranged round the segment and each type bar is connected by a link 3 to its key lever so that `any required type bar is turned about its pivot to make -an impression when the appropriate key lever is depressed.

Each type bar is provided with an labutment 4 thereon which is adapted, when the type bars reach a certain position, to engage with the edge of a flange 5 on a plate 6 mounted at the back `of the type bar segment. The ange .is arcuate in elevation `and is concentric with a line passing through the pivotal points of the type bars so that the abutment 4 on each type bar 1 will engage with the ilange 5 when the respective type bars 'are operated.

The plate 6 is supported in its position in any convenient manner and for this purpose it may be carried lby pins 13 and is held in its normal position by coil springs `disposed on the pins 13 or by leaf springs which are omitted from the drawings. It will however be understood that the plate 6 is rtree to move about `a fulcrum point and act as a lever when the flange 5 is engaged by and moved by an abutment 4 on any of the type levers.

For this purpose the plate 6 is normally held up to a raised part lor rib 7 on the back of the type Ibar segment 2 by the springs previously mentioned. When an abutment 4 on a type bar 1 engages the flange 5, further movement of the type bar as it moves towards the platen to make an impression, rocks the plate 6 labout the fulcrum point 8 Von :the edge of the rib '7 as shown in FIG. 3. This rocking movement of the plate 6 is utilized to operate the carriage escapement. For this purpose -a raised part 9 may be provided at the appropriate point on the plate 6 located thereon as hereinafter explained and this raised part 9 engages with an arm 10 pivoted at 11 in a back plate 12 secured to the back of .the type bar segment 2. The upper end of the varm 10 is connected to the carriage escapement in `any suitable way while its lower end is connected to the spacer 'bar of the machine.

If preferred the arm may be pivoted on lthe type bar segment and a projection provided on the arm to engage with the appropriate point on the plate 6. Alternatively the appropriate point lon the plate 6 may be connected directly to the carriage escapement.

FIGS. 1 and 3 show the centrally disposed type bar in the type bar `segment and it will be seen that the fulcrurn point of the plate 6 when this type bar is operated is at a point on the edge of the rib 7 which is on a line drawn from the point of engagement of the abutment 4 with the edge of the flange 5 through the centre of the raised part 9. Similarly for each type bar the fulcrurn point of the plate 6 is on a line drawn from the point of contact of the abutment 4 with the flange 5, through the centre of the raised part 9. For example, vfor a type bar engaging the ange 5 at A, see FlG. 2, the fulcrum point of the plate 6 will `be at B and for a type bar engaging the flange 5 at C, the fulcrum point will be at D.

It will be understood that for the correct operation of the carriage escapement the movement of the raised part 9 must be constant, whichever type bar is operated. The plate 6 acts as a universal lever and to provide for the constant movement of the raised part 9 by each of the type bars the edge of the rib 7 is an arc of a circle or substantially a circle of suitable diameter to provide fulcrum points for each type bar and the raised part 9 is located so that the distance from the -fulcrurn point to the centre of the raised par-t 9 over the distance from .the fulcrum point to the point of `contact of the type bar with the edge of the flange 5 is always constant. Consequently the movement of the raised part 9 by each type bar when operated to make an impression is the same.

The arrangement described provides a simple form of universal bar or bail requiring the minimum number of working parts and obviatcs either any alteration of the relative positions of the abutments on the type bars to compensate for their angular dispositions in the Itype bar segment yor curvature of the striking edge of the bail required when a pivoted bail is used.

What I claim is:

1. Typewriter carriage escapement operating mechanism comprising in combination a type bar segment, type bars including type bar levers pivotally mounted in the type bar segment, aruniversal bar mounted on the back of the type bar segment and being in the form of a pla-te, an arcuate flange -on one edge of the plate for engagement by the type bar levers, a fulcrum for the plate of arcuate lform, the fulcrum for the plate lbeing formed by the edge of a rib-like part on the back of the type bar segment, and a pivoted arm which engages With the plate and is adapted to connect the arm to the carriage escapement.

2. Typewriter carriage escapement operating mechanism according to claim l in which the plate is formed with a raised part thereon to engage the arm.

3. Typewriter carriage escapement operating mechanism according to claim 2 in which the arm is pivoted on a plate `secured to the back of the type bar segment.

4. Typewriter carriage escapement `operating mec-hanism according to claim 2 in which the arm is pivoted intermediate its ends, one end being connected to the carriage escapement mechanism `and the other end being adapted to lbe `connected to the spacer bar of the machine.

References Cited in the le of this patent UNTED STATES PATENTS 400,383 Yost Mar. 26, 1889 FOREIGN PATENTS 730,236 Great Britain May 18, 1955 

1. TYPEWRITER CARRIAGE ESCAPEMENT OPERATING MECHANISM COMPRISING IN COMBINATION A TYPE BAR SEGMENT, TYPE BARS INCLUDING TYPE BAR LEVERS PIVOTALLY MOUNTED IN THE TYPE BAR SEGMENT, A UNIVERSAL BAR MOUNTED ON THE BACK OF THE TYPE BAR SEGMENT AND BEING IN THE FORM OF A PLATE, AN ARCUATE FLANGE ON ONE EDGE OF THE PLATE FOR ENGAGEMENT BY THE TYPE BAR LEVERS, A FULCRUM FOR THE PLATE OF ARCUATE FORM, THE FULCRUM FOR THE PLATE BEING FORMED BY THE EDGE OF A RIB-LIKE PART ON THE BACK OF THE TYPE BAR SEGMENT, AND A PIVOTED ARM WHICH ENGAGES WITH THE PLATE AND IS ADAPTED TO CONNECT THE ARM TO THE CARRIAGE ESCAPEMENT. 